Multistation remotely controlled phonographic system



April 27, 1954 w. w. LOGAN MULTISTATION REMOTELY-CONTROLLED PHONOGRAPHIC SYSTEM Filed Dec. 26, 1951 sw H Snventor willam w. Eogam Gttorneg Patented Apr. 27, 1954 MULTISTATION REMOTELY CONTROLLED PHONOGRAPHIC SYSTEM William W. Logan, Glen Ridge, N. 3., assignor to Thomas A. Edison, Incorporated, West Orange, N. J a corporation of New Jersey Application December 26, 1951, Serial No. 263,317

9 Claims. (Cl. 179100.1)

This invention relates to multistation remotelycontrolled phonographic systems and particular- 1y to novel and improved means and arrangements for such systems for insuring privacy, and freedom from interference from others, to each user of the system, the term user being herein employed to mean the first of several operators at the remote stations to activate the phonographic system for use.

The invention is especially applicable to dictation-recording systems of the type wherein one dictating machine is adapted to serve a plurality of remote stations such, for example, as is disclosed in th pendin Somers et a1. application Serial No. 247,244, filed September 19, 1951, and entitled Remotely-Controlled Dictation Recording System, but no unnecessary limitation of the invention to systems of this type is intended.

The dictation-recording system just referred to comprises a plurality of remote operators stations connected in parallel to a single recording machine, the connections leading from each remote station comprising a combined communication and control circuit and a signal and/ or control circuit. In this system, warning is given at all idle remote stations via the signal circuits when the system is in use. But such warning does not, preclude others at idle stations from listening in to the dictation being recorded or reproduced by the user of the system, or from talking into their microphones to interfere with such reco-rdation or reproduction, or from manipulating their controls to interfere with the intended control of the system by the user.

An object of this invention is to provide a novel means and arrangement dependent on the voltage regulation in the phonographic system for assuring privacy and noninterferenoe from others to each user of the system. 7

Another object is to provide a conditioning control means for each remote station and a power source for operating this means, which power source has such voltage regulation that only the conditioning control means associated with the remote station in use is ever operated.

Another object is to provide a station-abling relay for each remote station having such voltage-operating characteristics that it will operate at the open line voltage available in the phonographic system when the system is activated and will not operate at the lower voltage available during use of the system.

Another object is to provide a station-abling relay which, once the same has been operated,

- 2 will be retained in operated position until the phonographic system is returned to inactivated condition.

A further object is to provide a signaling means in phonographic systems of the character here described for apprising each nonuser as to the disabled condition of his station.

As will appear, the present invention depends on a properly regulated voltage supply and on the provision of a station control relay at each remote station which is normally in a stationdisabling position and which has a voltage operating characteristic such that when the first of these relays is connected in circuit by the first prospective user this relay will be operated by the current surge present during transition from open to closed line. By this operation, the respective remote station is placed in operative condition. However, when a second prospective user connects his station-abling relay in the circuit while the system is in use, the available voltage will be insuflicient to operate that relay becaus of power supply regulation. As a result, only the first operator who attempts to initiate activation of the phonographic system will be enabled to do so.

The aforestated objects and features of my invention will be apparent from the following description and the appended claims.

In the description of my invention reference is had to the accompanying drawings, of which:

Figure 1 is a fractional diagrammatic showing of a multistation remotely-controlled phonographic system incorporating my invention; and

Figure 2 is a diagrammatic view of a modified form of remote station for the purposes or my invention.

Since the invention has special application in connection with dictation-recording systems of the type above-mentioned, it is herein particularly described in connection with this type of dictation-recording system, but only such portions of this dictating system are shown as need be considered for the purposes of the present invention.

As shown in Figure 1 the dictating system comprises a home or attendants station It and a plurality of identical remote operators stations of which there are two shown by way of example, these stations being referred to as Na and l lb respectively. At the attendants station there is a dictating machine 12 (fractionally shown) which comprises a turntable l3 driven by a motor l4 through a clutch. E5. The turntable carries a record disc 16 engaged by a recording unit ll.

Audio speech-representing currents are fed to this recording unit through an audio transformer l8 and a circuit is including an amplifier 2G.

The attendants station is provided with a communication or audio circuit 2| which serially includes the primary of the audio transformer 23. This communication circuit is used also to control the machine, and for the latter purposes it includes two serially-connected relays 22 and 23. Audio currents in the communication circuit are by-passed around these relays by acondenser .24. The communication circuit is energized from a low-voltage D.-C. power source (not shownb which is connected to the terminals 25 marked and respectively. The'rel-ays are adapted to operate at different levels of D.-C. current es tablished selectively at the operators stations as will appear. Relay 22 has contacts 2'6 operated at the lower current level to close the power circuit 2? serially including the motor 14. This power circuit is energized from an A-C. source (not shown) which is to be connected to the terminals 28. The second relay 23 is adapted to operate at a higher level of current and controls the clutch in as represented diagrammatically by the tie-line 23a. These relays may or" course perform still other control functions which need .not however be herein described. For the pres- :ent purposes, it will be understood that the motor [4 is started when the relay 22 is operated and that the clutch i5 is engaged to start rotation of the turntable l3 when the relay 23 is operated. An energization of the communica tion circuit 2| at the lower current level, with the resultant starting of the motor it, is herein 2.:

considered as an activation of thedictating system.

In the powercircuit Z1 and in shunt with the motor 14 there is a voltage stepdown transformer 29 the secondary of which is connected to two outgoing leads constituting a signal circuit 30 for the dictating system. This signal circuit is accordingly energizedwhenever the dictating system is activated.

The operators stations I la and [lb are identical and a description of the station He will suffice for the other. Corresponding elements of these stations are given the same reference numerals but with the suffix letters of the respective stations.

Branch communication circuits lead from the main communication circuit 2| to each remote station and are referred to by the numeral 21 with the sufiix letter of the respective station. Likewise, branch signal circuits lead from the main signal circuit 30 to each remote station referred to by the numeral 39 with the suiiix letter of each remote station.

The station Ha has a handpiece 31a, for example, of the usual telephone variety including,

as transducer elements, the carbon button microphone 32a and receiver 33a each of which is connected across the respective branch'communication circuit 2511 when the remote station is conditioned to activate the system for use. Also, the remote station has an on-off station switch 34a of the double-pole two-position type one pole 35a of which is connected in the negative side of the branch circuit Zia and the other pole 35a of which is connected in one side of the branch signal circuit 30a. The station switch is biased closed (into on position) by a tension spring 31a but is held open by weight or" the :handpiece placed as on .a hooked extension 38a of the pole 35a, when the .station is :not in use,

The branch signal circuits serially include re spective signal lamps referred to by the number 38 with the sufiix letter of the respective station. These lamps provide a busy signal at each remote station when the phonographic system is activated for use.

In accordance with my invention each remote station is provided with a station-conditioning apparatus, preferably in the form of a relay, which normally retains the station in a disabled condition. With reference, for example, to station Ha, this relay a has a coil section sla serially connected in the branch circuit 21a for vienergization from the D.-C. potential source, 'represented by the terminals 25, when the respective station switch 34a is closed. Because of the resistance of the relay coils 22 and 23 and of the primary winding of the audio transformer I8 in the communication circuit 2| at the attendants station, the regulation of the voltage source 25 is poor at the remote stations, causing the voltage at these stations .to .fall substantially when any one of the station relays is connected in circuit. The voltage operating characteristics of these station relays are such that each requires a relatively high operating voltage and a low holding voltage; thus a station relay will operate from the current surge available, especially from the charged condenser '24, when the -fil'St user closes his station switch and will be retained in operative position at the lower supply voltage which is available after the station switch is closed. This lower voltage supply in the branch circuits is however insufficient to operate any of the remaining station relays. Accordingly if a second prospective user closes his station switch his relay will not be operated. Thus, the onlystation relay which is operated is that one at the first users station.

When, say at station I la, the station relay 40a is operated by a first user closing the station switch 34a, a switch .pole 42a and contact 43a of this relay are closed to connect the receiver 33a across the branch communication circuit .ila by way of the pole 35a of the stationswitch, condenser t in, pole 56a of the station switch, line 45a, condenser 460 resistor Ala, relay pole tic, contact eta, and condenser 4841; also, the microphone -B2a is now connectable across the branch communication circuit by way of the pole 35a, line 39a, start-stop switch 56a, relay pole i'Za, contact 430. and condenser 413a. Whenever the start-stop switch a is closed there is also pro vided a D.C. connection to the microphone across the branch communication circuit by way of a second coil section .E'la of the station relay. (The aforementioned condenser 48a paralleling this coil section is provided to form a low-impedance shunt for the audio currents around this coil sec tion.)

In View of this additional D.-C. current path at the remote station, the D.-C. level of current in the branch communication circuit is increased to cause operation of the relay 23 at the attendvants station. Operation of this relay closes the clutch is to start record rotation as before explained. Also, this additional component of D.-C. current in the coil section 5 l a serves, in view of the two coil sections of the station relay being poled additively, to aid in holding the relay in operated position especially at such times when other prospective users may close their station switches and cause a further drop in'line voltage at the remote stations.

lf while the phonographic system is in use a prospective second user lifts his handpiece from its support, not only will his station relay fail to operate as above described but because of this failure he will receive a heavy hum or signal in his receiver to apprise him definitely that the system is being used by another and that his station is in a disabled condition. This signal is fed to the receiver from the respective branch signal circuit. For example, if the operator at station I lb lifts his handpiece while the operator at station Ha is using the system, the signal circuit from the branch 36b to the receiver 33b is completed via pole 36b of the station switch, line 45b, condenser 46b, resistor 47b, pole 42?), contact 521) of the station relay and line 531).

When the phcnographic system is activated by the first users closure of his station switch, this user is enabled to record dictation spoken into his microphone and is enabled also, at will, to reproduce portions of his recorded dictation. For recordation, the user presses and releases switch 56a to start and stop the machine as beforementioned. To reproduce, he need only press a 1 separate switch designated by the numeral 54 with the suffix letter of the remote station. When this switch is closed a relay 55 is operated at the attendants station. This relay '55 is connected by a line 56 between the positive side of the communication circuit 2! and one side of the signal circuit 35 to receive operating current from the potential source by way of the line 56, one side of the. communication circuit and of the branch circuit 36a, switch 54a, pole a of the station switch 34a, and negative side of the branch communication circuit Zia and communication circuit 2! to the negative side of the potential source 25. The relay 55 controls a double-pole switch 51 and the clutch I '5. Switch 51 is normally positioned to connect the audio transformer l8 to the recording amplifier 26. operated the switch 51 shifts the connection of the audio transformer to a reproducing amplifier 53 in a line 59 leading to a reproducer 60. This reproducer engages the record at a trailing distance behind the recorder. Thus, as the reproducing control switch 54a is closed at the remote station, the machine is conditioned for reproduction and record rotation is started to enable reproduction of a portion of the recorded dictation. If desired, the reproducer may be mounted so that it may be selectively positioned to reproduce any desired portion of the record according to known practice but means for doing this need not be shown for the purposes of the present invention.

By way of illustrative example, the open line voltage in the communication circuit may typically be about volts, the voltage at the remote stations when one station switch is closed to connect the respective station relay to the power supply may be of the order of 30- volts, and the voltage at the remote station when the start-stop switch 56 is also closed may be only 5 volts. The resistance associated with the voltage source (including the resistance of the primary of the audio transformer i6, and of relays 22 and 23) may be of the order of 300 ohms and that of each station relay of the order of 700 ohms. Efach station relay should be of a type that will pull ini. e., operateat an app-lied voltage of the order of 30 volts and will hold ini. e., stay operated-at an applied voltage of the order of only 4 volts.

In Figure 2 there is shown a second form of remote station I I0 for phonographic systems according to my invention, which differs from the.

AS the relay 1 mi foregoing only as to details. Branch communication and branch signal circuits lead to this station, the same as before, and are'referred to as 2 10 and 360 respectively. Elements of the station per se which are the same as corresponding elements of the station above described are given the same reference numerals but without suffix letters.

The station has a handpiece 3! comprising microphone and receiver units 32 and 33, a recording start-stop switch 56, condenser and resistor elements 46 and 41 in the circuit of the receiver 33, a double-pole station switch 34, signal light 39 and a reproduce start-stop switch 54. The station switch comprises one pole 35 in the communication circuit and one pole 36 in the signal circuit. The station relay, here referred to as 6!, may comprise a single coil, as shown, connected at one end to the negative side of the communication circuit and at the other end to a contact 52 associated with the switch pole 35. If the station switch is closed the pole 35 makes with contact 62 to connect the station relay across the communication circuit.

The station relay comprises two poles 64 and connected by a line 66 and the condenser and resistor elements 46 and 4'! to the receiver 33, and connectable also by way of the line 66 and the start-stop switch 56 to the microphone 32. The relay poles 64 and 65 make respectively with contacts 6i and 68 when the station relay is not operated. The contact 61 is connected by a line 69 to one side of the signal circuit, and contact 68 is connected by a line iii to the contact 63 associated with the station switch pole 36. When the station relay is operated, the poles 64 and 65 break with the contacts 61 and 68 and make respectively with contacts H and 12. The contact H is connected by a line 13 to the contact 62 associated with the station switch pole 35, and the contact 72 is connected directly to the negative side of the communication circuit.

If the operator at station He is the first to close his station switch, effective voltage will be available to cause operation of the station relay 6i. Operation of this relay will cause the line 66, which includes the receiver and microphone units, to be connected to the communication circuit through the relay switch poles 64 and 65, the respectively associated contacts II and 12 and the contact 62 and pole 35 of the station switch. The station will thus be conditioned for normal use both for recording and reproducing, the start-stop operation for recording being controlled by the hand switch 56 and the startstop operation for reproducing by the hand switch 54.

On the other hand, if insufficient voltage is available in the communication circuit to operate the station relay when the station switch is closed, because of an operator at some other station having previously activated the system for use, the closure of the station switch will serve only to connect the signal circuit to the receiver 33. This connection will be made from one side of the signal circuit through the station switch pole 36 and contact 63, line 16, contact 68 and pole 65 of the station relay, and one side of a line 66 to one terminal of the receiver 33, and thence from the other terminal of the receiver through the condenser 46, resistor 41, the other side of the line 66, pole 64 and contact 61 of the station relay and the line 69 to the other side of the signal circuit. Thus, closing the station switch while the system is in 7 use will cause signal current to be fed-to :the receiver to produce therein aheavy hum. This =h1un will serve to:apprise"the-operator immediately as to thedisabled condition ofhis station.

The foregoing embodiments of my invention :remote stations to said machine whenthe re- .spective station switchis closed; means for sup- ".plying energizing "potential to said branch circuits-from said potential source; respective disabling switches connected to said branch :ciricuits and movableinto effective and ineifective positions for rendering inoperative and operative the respective remote stations; respective electriically-energizable devices for operating said' disabling switches normally positioned to render the stations inoperative and connected. in the respective branch circuits for operation by said potential source to render the respective stations operative upon closure of the respective station switches; and means connected in circuit with said potential source and effective upon closure of of branch circuits for reducing the voltage to said branch circuits to a value insufficient to operate any subsequent one of said energizable devices.

2. In a remotely-controlled multistationphonographic-system including a source of potential: the combination of an attendants station including a phonographic machine; a'plurality of remote operators stations each including a transducer and an on-off'station switch; circuit means includingbranch circuits leading from said remote stations respectively for connecting said remote stations to said -machine when the respective station switch is closed; means for supplying energizing potential to said branch circuits from said potential source; respective disabling switches connected in said branch circuits operableinto effective and ineiiective positions for rendering operative and inoperative the respective remote stations; respective electrically-energizable devices for operating said disablng switches normally positioned to render the stations inoperative and connected in the respective branch circuits for operation by said potential source upon closure of the respectively associated station'switches to render the respective remote stations operative; and resistance and capacitance means connected in circuit with said source of potential to make available an initial high-voltage surge current to said branch circuits and to cause the voltage to said branch circuits to fall substantially when one of said energizable devices is connected across said potential source, each of said 'energizable devices having a voltage operating characteristic such that it'is operable 'by'the initial current surge available when the first of said branch circuits is closed and such thatthe remaining devices are inoperable bythe voltage available at the remote stations after-said'one 'device'is operated.

i3. The-combination set .forth claim;2 wherein each-of saidenergizabledevices and respective disabling switches is a relay having a low voitage-drop-out characteristic causing the operated one of the relays to be retainediniop- .erate'd position by the voltage available at the :respective remote stationwhenall of said branch "circuits are 'closed.

Ina remotely-controlled multistation phonographic system including a source of 'Dr cn'posistance means connected in circuit with said potential source to cause :a substantial decrease in the line voltage at the remote stations-when one -'of said branch circuits is closed; respective relaysifor said remote stations connected in'the rrespectivebranch circuits for operation by said potential source as the-respective station switches closed, each of said relays having avoltage characteristic such that it is operable by the open-circuit line voltage existing in said branch circuits whenthe first of said circuits isclosed and-isuchthat it is inoperable "by'th'e line voltages .atatheremote stations when another one of said station switches is already closed; and switch means in each relay for'connecting the respective transducer to saidmachine as the relay is operated.

5. The combinationset forth in claim' wherein eachof said relays comprises a coil section connected seriallyin the respective branch cirtcuit for operating the relay upon the respective station switch being first to be closed, and wherein eachof said relays includes'a second coil section-and switch means to connect said second sectionin :said branch circuit in series with the :respective transducer as the relay is operated, said. second coil section being poled to be in :additive relation with said first coil section so that th current through the transducer will aid in'h-olding'the'relay in operated position at the reduced line voltages present after the relay is operated.

The combination set forth in claim a, including means for feeding signal current to each ofsaid'remote stations during use of the phonographic system,iand switch means controlled by ceachof said relays for connecting said signalfeeding means to the-respective transducer when the relay is in unoperated position.

7. In a remotely-controlled multistation phonographic system including a source of potential: the combination of an attendants station including a phonographic machine; a plurality of remote operators stations each including a transducer and an on-ofi station switch; circuit means including: branch communication circuits leading from said remote stations respectively for connecting any selected one of said transducers tosaidrnachine via the respective station switch and branch circuit when that station switch is in on position; means connecting said 'potential source to said circuit means to supply energizing potential to each of said branch circuits; a relay at each of said remote stations having a coil connected for energization by said potential source via the respective branch circuit and station switch when the station switch is in on position; means connected to said potential source to cause a substantial drop in potential in said branch circuits at said remote stations when one of said relays is connected in circuit, each of said relays having a voltage operating characteristic causing the relay to operate from the initial voltage available as the first of said station switches is moved to on position and to be inoperable by the voltage available after one of said relays is connected in circuit; and each relay including switch means connected in the respective branch circuit for disconnecting the respective transducer therefrom when the relay is not operated and for connecting the respective transducer thereto when the relay is operated.

8. The combination set forth in claim 7 including a source of signaling current, a branch signal circuit leading from said signal source to each of said remote stations, and circuit means at each remote station including the respective station switch and a switch means of the respective station relay for connecting said signaling source to the transducer of said remote station only when said relay is unoperated and said station switch is in on position.

9. In a remotely-controlled multistation phone graph system including a D.-C. source of potential: the combination of an attendants station including a phonographic machine; a plurality of remote operators stations each including a transducer and a station switch movable into on and off positions; means connected to said potential source for supplying standby power to each of said remote stations; means responsive to movement of any one of said station switches to on position for activating said phonographic machine for use; a station conditioning relay at each remote station normally in a station disabling position and efiective when operated to render the station operative, each of said relays being operable at the normal voltage of said potential source and being unoperable at voltages substantially lower than that of said source, and each of said relays being connectable to said potential source via the respective station switch as the latter is moved to on position; and resistance means in the circuit of said potential source eiTective upon one of said relays being operated to cause the voltage available at the remaining remote stations to be insufiicient to operate any or" the remaining conditioning relays.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,066,672 De Berand et al. Jan. 5, 1937 ,20 Chenoweth et al. Mar. 24, 1942 2,284,306 Sparling May 26, 1942 2,333,235 Clausen Nov. 2, 1943 

